Let PDB.get_tag convert normalization errors to NoSuch.

Instead of having to account for them on the other end,
since they don't care about that stuff anyway.

etiquette/photodb.py

@@ -831,7 +831,11 @@ class PDBTagMixin:
 
         tagname = tagname.strip('.+')
         tagname = tagname.split('.')[-1].split('+')[0]
-        tagname = self.normalize_tagname(tagname)
+
+        try:
+            tagname = self.normalize_tagname(tagname)
+        except (exceptions.TagTooShort, exceptions.TagTooLong):
+            raise exceptions.NoSuchTag(tagname)
 
         cur = self.sql.cursor()
         while True:

etiquette/searchhelpers.py

@@ -423,12 +423,7 @@ def normalize_tag_mmf(tags, photodb, warning_bag=None):
 
         try:
             tag = photodb.get_tag(name=tag)
-            exc = None
-        except exceptions.NoSuchTag as e:
-            exc = e
-        except (exceptions.TagTooShort, exceptions.TagTooLong) as e:
-            exc = exceptions.NoSuchTag(tag)
-        if exc is not None:
+        except exceptions.NoSuchTag as exc:
             if warning_bag:
                 warning_bag.add(exc.error_message)
                 continue